High voltage supercapacitor is possible?

In summary, the energy density of a supercap is equal to square of it's voltage. The best dielectric materials for supercaps are not carbon, but instead barium titanate. If we replace carbon with barium titanate, it is not going to be charged even up to 30 volts. The present state-of-the-art for supercaps is limited in voltage per cell of 2.8 volts because of the thin dielectric. The maximum capacitance however is 3000 farads. To use in most any application these are put into banks, both series and parallel, until the needed operating voltage (series) and capacitance (parallel) are achieved. The only fly in this ointment is that
  • #1
Stanley514
411
2
Energy density of supercap is equal to square of it`s voltage.
Is it possible to join together advantages of supercaps and high voltage
capacitors such as Ferroelectric caps?
What prevents to use high-k materials in supercaps?
 
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  • #2
dielectric brakedown. To have large capacitance, you need your plates to be very close to one another (micrometer or nanometer range). Now imagine having opposite charges so close to one another - the forces are enormous and the material will break, or in the best case, leak.
 
  • #3
What do you think on following project:
http://www.technologyreview.com/energy/22297/" [Broken]
Do you think it is going to fail?
Well,we could charge usual carbon supercap up to 4 volts only,
But carbon is far from best dielectric materials.Do you want to say
that if we will replace carbon with such material as barium titanate
it is not going to be charged even up to 30 volts?
 
Last edited by a moderator:
  • #4
The present state-of-the-art (an example is Maxwell UltraCapacitor) is limited in voltage per cell of 2.8 volts because, as Curl reported, of the thin dielectric. The maximum capacitance however is 3000 farads (not micro, but farads). In order to use in most any application these are put into banks, both series and parallel, until the needed operating voltage (series) and capacitance (parallel). The only fly in this ointment is that the cells require a balancing circuit due to internal variations in leakage. This leakage, if unchecked, will allow some cells to exceed the 2.8 volt limit. Leakage current is microamps so any variation in internal resistance will cause a large voltage variation.
 
  • #5
Stanley514 said:
What do you think on following project:
http://www.technologyreview.com/energy/22297/" [Broken]
Do you think it is going to fail?
Well,we could charge usual carbon supercap up to 4 volts only,
But carbon is far from best dielectric materials.Do you want to say
that if we will replace carbon with such material as barium titanate
it is not going to be charged even up to 30 volts?

30 volts with nano-scale spacing is a very large field. No matter what material you put in between (or even a vacuum) will allow charge to jump across if the field is strong enough.
Even if this doesn't occur, like I said, it will leak charge and the capacitor will discharge by just sitting there.
 
Last edited by a moderator:
  • #6
Stanley514 said:
Well,we could charge usual carbon supercap up to 4 volts only,
But carbon is far from best dielectric materials.Do you want to say
that if we will replace carbon with such material as barium titanate
it is not going to be charged even up to 30 volts?

Carbon is not a dielectric at all. Supercapacitors don't have a dielectric. They use an electric double layer instead.
http://en.wikipedia.org/wiki/Electric_double-layer_capacitor
 
  • #7
Carbon is not a dielectric at all. Supercapacitors don't have a dielectric. They use an electric double layer instead.
So what we would theoretically to do to increase voltage of supercup?
Find another electrolyte?
 
  • #8
You increase space between plates... but if you do that, you lose capacitance. Its a trade.
 
  • #9
How could we calculate theoretical capacitance of supercapacitor (in Farads/g) knowing
its surface area per gram?For example surface are is 2.000 m2/g.What would be capacitance if all this area is ideally utilized?
 

What is a high voltage supercapacitor?

A high voltage supercapacitor is a type of energy storage device that can store and release large amounts of electrical energy at high voltages. It combines the high energy density of a battery with the high power density of a traditional capacitor.

How does a high voltage supercapacitor work?

A high voltage supercapacitor works by storing energy in an electric field rather than through chemical reactions, like a battery. It consists of two electrodes separated by an electrolyte, and when a voltage is applied, ions in the electrolyte are attracted to the electrodes, storing energy in the electric field. When the supercapacitor is discharged, the stored energy is released as the ions return to the electrolyte.

What are the advantages of high voltage supercapacitors?

High voltage supercapacitors have several advantages over traditional batteries, including a longer lifespan, faster charging and discharging times, and the ability to operate at a wide range of temperatures. They also have a higher power density, meaning they can deliver more energy in a shorter amount of time.

Are high voltage supercapacitors safe?

High voltage supercapacitors are generally considered safe because they do not contain toxic chemicals or emit harmful gases. However, they can still pose a risk of electric shock if mishandled or damaged. It is important to follow proper safety protocols when working with high voltage supercapacitors.

What are the potential applications of high voltage supercapacitors?

High voltage supercapacitors have the potential to be used in a wide range of applications, including electric vehicles, renewable energy storage, and portable electronics. They can also be used in combination with batteries to improve overall energy efficiency and performance. Research is ongoing to further explore and develop the capabilities of high voltage supercapacitors.

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